The worst thing about dialogue is when the author attempts to convey a thick accent. Too often it ends up with whole sentences made up of words spelled "wrong" or clipped with apostrophes all over the place.
Deliberate misspelling to convey dialect pronunciation or to suggest the speech of people who are illiterate or poorly educated is called "eye dialect."
It's been used by many notable authors but is considered rather un-P.C. nowadays.
Oh, and I have the same issue with foreign / alien character names. If they're too weird, it makes my brain stumble every time I see it. I have a character in a story named Sarisha Sahani. She is of Indian decent (Hindu, not Native American), so she has a unique name, but it's not unpronounceable.
I've often wondered why so many aliens in science fiction have names with apostrophes in them. Other planets' languages must be full of glottal stops.